require 'optparse'
require 'socket'
require 'fileutils'
def daemonize #:nodoc:
exit if fork # Parent exits, child continues.
Process.setsid # Become session leader.
exit if fork # Zap session leader. See [1].
Dir.chdir "/" # Release old working directory.
File.umask 0000 # Ensure sensible umask. Adjust as needed.
STDIN.reopen "/dev/null" # Free file descriptors and
STDOUT.reopen "/dev/null", "a" # point them somewhere sensible.
STDERR.reopen STDOUT # STDOUT/ERR should better go to a logfile.
end
class Spawner
def self.record_pid(name = "#{OPTIONS[:process]}.spawner", id = Process.pid)
FileUtils.mkdir_p(OPTIONS[:pids])
File.open(File.expand_path(OPTIONS[:pids] + "/#{name}.pid"), "w+") { |f| f.write(id) }
end
def self.spawn_all
OPTIONS[:instances].times do |i|
port = OPTIONS[:port] + i
print "Checking if something is already running on port #{port}..."
begin
srv = TCPServer.new('0.0.0.0', port)
srv.close
srv = nil
print "NO\n "
print "Starting FCGI on port: #{port}\n "
FileUtils.mkdir_p(OPTIONS[:pids])
spawn(port)
rescue
print "YES\n"
end
end
end
end
class FcgiSpawner < Spawner
def self.spawn(port)
system("#{OPTIONS[:spawner]} -f #{OPTIONS[:dispatcher]} -p #{port} -P #{OPTIONS[:pids]}/#{OPTIONS[:process]}.#{port}.pid")
end
end
# TODO:
# class MongrelSpawner < Spawner
# def self.spawn(port)
# end
# end
OPTIONS = {
:environment => "production",
:spawner => '/usr/bin/env spawn-fcgi',
:dispatcher => File.expand_path(RAILS_ROOT + '/public/dispatch.fcgi'),
:pids => File.expand_path(RAILS_ROOT + "/tmp/pids"),
:process => "dispatch",
:port => 8000,
:instances => 3,
:repeat => nil
}
ARGV.options do |opts|
opts.banner = "Usage: spawner [options]"
opts.separator ""
opts.on <<-EOF
Description:
The spawner is a wrapper for spawn-fcgi that makes it easier to start multiple FCGI
processes running the Rails dispatcher. The spawn-fcgi command is included with the lighttpd
web server, but can be used with both Apache and lighttpd (and any other web server supporting
externally managed FCGI processes).
You decide a starting port (default is 8000) and the number of FCGI process instances you'd
like to run. So if you pick 9100 and 3 instances, you'll start processes on 9100, 9101, and 9102.
By setting the repeat option, you get a protection loop, which will attempt to restart any FCGI processes
that might have been exited or outright crashed.
Examples:
spawner # starts instances on 8000, 8001, and 8002
spawner -p 9100 -i 10 # starts 10 instances counting from 9100 to 9109
spawner -p 9100 -r 5 # starts 3 instances counting from 9100 to 9102 and attempts start them every 5 seconds
EOF
opts.on(" Options:")
opts.on("-p", "--port=number", Integer, "Starting port number (default: #{OPTIONS[:port]})") { |OPTIONS[:port]| }
opts.on("-i", "--instances=number", Integer, "Number of instances (default: #{OPTIONS[:instances]})") { |OPTIONS[:instances]| }
opts.on("-r", "--repeat=seconds", Integer, "Repeat spawn attempts every n seconds (default: off)") { |OPTIONS[:repeat]| }
opts.on("-e", "--environment=name", String, "test|development|production (default: #{OPTIONS[:environment]})") { |OPTIONS[:environment]| }
opts.on("-n", "--process=name", String, "default: #{OPTIONS[:process]}") { |OPTIONS[:process]| }
opts.on("-s", "--spawner=path", String, "default: #{OPTIONS[:spawner]}") { |OPTIONS[:spawner]| }
opts.on("-d", "--dispatcher=path", String, "default: #{OPTIONS[:dispatcher]}") { |dispatcher| OPTIONS[:dispatcher] = File.expand_path(dispatcher) }
opts.separator ""
opts.on("-h", "--help", "Show this help message.") { puts opts; exit }
opts.parse!
end
ENV["RAILS_ENV"] = OPTIONS[:environment]
if OPTIONS[:repeat]
daemonize
trap("TERM") { exit }
FcgiSpawner.record_pid
loop do
FcgiSpawner.spawn_all
sleep(OPTIONS[:repeat])
end
else
FcgiSpawner.spawn_all
end
